This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Various types of vehicles have been developed to sweep or vacuum debris from pavements, roadways, and streets. In general, these vehicles can be classified as mechanical broom sweepers, regenerative air sweepers, vacuum sweepers, and, in some cases, combinational variants thereof.
Mechanical broom sweepers use a motor-driven broom or brooms to mechanically sweep paper, plastic, litter, trash, vegetation (leaves, twigs, grass clippings, etc.), asphalt debris, concrete debris, and larger sand or gravel particles toward and onto a conveyor for transport into a debris collection hopper.
Regenerative air sweepers use a motor-driven fan to create a high-velocity recirculating air flow to entrain dust, particulates, and other debris from the pavement or street surface. The recirculating air flow may be passed through a debris container or hopper that includes various types of partitions, screens, and/or baffles that are designed to slow the airflow and cause the entrained debris to collect in the debris hopper.
Vacuum sweeper vehicles use a motor-driven fan to develop a sub-atmospheric pressure within the vehicle air flow pathway(s) so that ambient air at atmospheric pressure enters a suction-inlet or suction-inlets to create a suction effect to entrain debris into the air flow. The debris-entrained air flow may be delivered to the debris-collecting hopper where the debris may be separated from the air flow with the air flow being exhausted from the sweeper vehicle. Brooms are often used to move debris in the direction of the suction-inlet to improve sweeping efficiency. For example, a cylindrical tube broom may be aligned in a side-to-side alignment (or at a selected angle) in relationship to the direction of travel to move debris toward the suction-inlet.
Optionally, a side-broom (also known as a gutter broom) carried on a pivotally mounted arm may be mounted on one or both lateral sides of the sweeper vehicle to brush debris into the path of an intake hood (also known as a pick-up head).
While tube brooms may be effective where the road surface is flat, many streets and road surfaces have an irregular profile. For example, many road surfaces are intentionally crowned in the center of the roadway and may also have unintentional spaced-apart depressions caused by the front and rear tires of heavy vehicles. In these situations, a tube broom may efficiently sweep the raised surfaces but in some instances may be less effective or ineffective for sweeping the depressed areas. It is common for the tube broom to wear unevenly and often become tapered at one or both opposite ends (a condition known as “coning”).
It would be a significant advancement in the art to provide an improved sweeper vehicle that may be more effective in sweeping road surfaces having a variety of different profiles.